Apparatus for drying printing plates



June 14, 1938. .1. PETERSA ET AL APPARATUS FOR DRYING PRINTING PLATESFiled June 14, 1955 2 Sheets-Sheet l June 14, 1938. J. EETEE'E ET AL2,120,471

' APPARATUS FOR DRYING PRINTING PLATES Filed June 14, 1955 2sheets-sheet 2 BY d m ATTORNEYS Patented June 14, 1938 UNITED STATESPATENT OFFICE APPARATUS POR DRYING PRIN TIN G PLATES John Peters,Teaneck, N. J., and Harold M. Crosby, Jackson Heights, N. Y., assignorsto News Syndicate Co. Inc., New York, N. Y., a corporation of New YorkApplication June 14, 1935, Serial No. 26,552

5 Claims.

the plate is turned more rapidly, after the supplyv of heat has beenshut olf.

Another object of our invention is to provide apparatus whereby thesupply of heat is automatically shut off after a predetermined intervaland the plate is then whirled or otherwise agitated at a higher speed.

Another object of our inventionis to provide an improved control wherebygas heat can be utilized, the supply of gas being automatically shut offafter a specified time interval and the whirling of the plate being thencontinued at a higher speed for an additional and predetermined timeinterval.

Another object of our invention is to provide improved time-switch meansfor said apparatus.

Other objects of our invention will be set forth in the followingdescription and drawings which illustrate a preferred embodimentthereof, it being understood that the above statement of the objects ofour invention is intended to generally explain the same Without limitingit in any manner.

Fig. 1 is an elevation of the improved apparatus.

Fig. 2 is a diagrammatic representation of the printing plate which isto be dried.

Fig. 3 is a top plan view on the line 3-3 of Fig. 1.

Fig. 4 is a sectional view on the line 4-4 of Fig. 1.

Fig. 5 is ya diagrammatic representation of the wiring circuits.

Fig. 6 illustrates a detail of the mechanism.

Heretofore and in preparing photo-mechanical printing plates, it hasbeen customary to dry said plates after they have been cleansed, bywhirling said plates in a heated atmosphere. According to previouspractice, the plate has been whirled about a vertical axis, with the wetcoating material at the bottom surface of the plate.

According to our improved method the plate is whirled in a heatedatmosphere, and the supply of gas or other heating medium is thendiscontinued, and the whirling of the plate is continued until thetemperature to which the plate is exposed has dropped from about 50 C.to 35 C. In treating the plate according to our improved method, theplate is-whirled about a verticalaxis in the usual manner and thecoating solution or material may be at the bottom surface y of theplate.

The improved machine has aframe F, provided at its top with acylindrical' compartment 56a,

-which has an open portion 56 at the front thereof. A slidable doorflJcan be provided if desired, and this door D can be moved vertically inguides 5I.

The door D may be closed or it may be held open or partially open, whilethe apparatus is being used.

The upper end of the apparatus is provided with a motor 2, which may bea three-phase electric motor. Said motor may have two speeds, as will belater more fully described.

The time switch 3 is also mounted at the top of the frame.

The motor shaft S is connected to a collar 5 by means of a suitable pin,so that the collar 5 turns with the motor shaft S. At its lower end thecollar 5 is provided with a pin 33, which is located in the slot 32 of ashaft extension 4. The shaft extension 4 can be moved up and downrelative to the collar 5, and the engagement of the pin 33 with the slot32 of the shaft extension 4, causes said shaft extension 4 to turn inunison with the shaft S.

'I'he shaft extension 4 is connected by a universal -jolnt 6 with asecond shaft extension 4a. Said shaft extension 4a has a reducedbottomportion, which is located within the groove of a third shaft extension4b, so that the members 4b and 4a turn in unison. The shaft extension 4bis provided with a collar I4, which is clamped thereto by means of ascrew I5.

The collar I4 rests upon the upper end of a cylindrical bearing I2. Ifdesired, any suitable antifriction means can be used, in order to permitthe collar I 4 to turn freely relative to the bearing I2. 7

As shown in Fig. 4, the cylindrical bearing I2 is connected to the outerend of a rod 8, which is slidable in a sleeve 1a. Thesleeve 1a isconnected to the interior wall of the compartment 56a, by means of anarm or bracket 1..

The slidable rod 8 is provided with a reduced shank Il, which isprovided with a head I0. A coil spring 9 surrounds the reduced shank II.One end of the coil spring 9 abuts the head I0,

and the other end of the coil spring 9 abuts a. shoulder of the sleeve1a. The coil spring 9 therefore yieldably retains the slide rodf8 in theposition shown in Fig. 4, but said slide rod 8, together with thebearing I2, can be pulled outwardly, if desired.

As shown in Fig. 6, the rod 8 is provided with an extension 8a whichfits within a corresponding groove of the sleeve 1a, when the parts arein the position shown in Fig. 4 and Fig. 6. However, when the rod 8 ispulled to lits outer posil tion, the extension 8a moves out of saidgroove of sleeve 1a, so that the sleeve 8 can be turned in unison withthe head I0. If desired, the shank II could be made turnable relative tothe head I0, so as to eliminate friction. Hence the vertical cylindricalbearing I2 can be turned around an axis which is perpendicular to theplane of Fig. 1, if the shaft member 4a is released from the shaftmember 4b. The shaft member 4a can be released from the shaft member 4bby pushing the shaft member 4a upwardly, this being permitted by the pin33 and the grooves or slots 32.

When the shaft member 4a is moved upwardly so as to release the collarI4, the shaft member 4a can be turned by means of'the universal joint 6,until said shaft member 4a is engaged by the resilient latch-member 36.This makes it possible to turn the bearing I2, in the manner previouslystated.

Referring to Fig. 4, the lower end of the shaft member 4b is integralwith a slotted arm I5.

Clamping members I1 are slidably mounted in the slots or grooves of theslotted arm I5, and said members I1 can be clamped in position relativeto the slotted arm I5.

As shown in Fig. 1, the clamping members I1 are provided with anges I8which engage the underside of the printing plate I. Hence the printingplate I can be clamped firmly in position at the bottom of the shaftmember 4b.

The compartment 56a is provided with a series of gas burners I9 and itis also provided with a ue 50, in order to permit the escape of theproducts of combustion. The burners I 9 are connected by means of handoperated valves 20, to a gas pipe 2I. The gas pipe 2| is connected to agas supply pipe 22, and a hand operated valve 3| can be operated inorder to shut oi the supply of gas to the burners.

The supply of gas to the burners is also controlled by an automaticallyoperated valve 30, this being operated by a solenoid or by othersuitable electro-magneticmeans. A pilot light 23 is aso provided and.this is connected to the pipe 2 v By means of this apparatus it ispossible to whirl the printing plate I in a heated atmosphere so as tothoroughly dry the same. 'I'he electric motor 2 is provided with currentthrough the lcable 24 which passes through a conduit 26.

'I'he apparatus is provided with a hand switch 25 for opening andclosing the circuit of the motor. A

As shown in Fig. 3, a cable which is locate in a conduit 1li, connectsthe motor to the switches which are diagrammatically shown in Fig. 5,and which are located in a switch casing 21. The conduit 10 carries thesix leads from the two switches in the control box to the windings ofthe motor. y

On the other side of the switch casing 21, a. conduit 28 is provided forthe cable of a branch control circuit to which the solenoid 61 (shown inFig. 5) is connected.

The wiring diagram shown in Fig. 5 may be analyzed as follows:-

Since the specific embodiment has a threephase motor, we have shownthree leads A, B, and C. A switch 31, having three arms, is connected toa rod 38 which is operated by means of the usual solenoid 38. When theswitch 31 is in the operative position the three arms thereof contactwith the three contact points 31a.

Another and similar switch 60 is provided, and this is operated by meansof a rod 6I, which is operated by means of the solenoid 62. When theswitch 60 is in the circuit-closing position, its three arms contactwith the points 63.

The lead A passes through the time switch 3 and its circuit includes thearmature 64 which is operated by means of the solenoid 65. Said parts 64and 65 diagrammatically illustrate a time-delay relay which may be ofany suitable conventional construction, so that a predetermined periodof time must elapse before the relay 64 is moved so as to close contactbetween the points 66, when solenoid 65 is energized.

When the armature 64 is in the circuit-closing position which isillustrated in Fig. 5, the current passes through solenoid 38, to thelead C. Hence, when the time switch 3 rst closes the circuit, thesolenoid 38 is energized, thus moving the rod 39, so that the switch 31moves to the circuit-closing position, in which position the coils 2a ofthe 'motor 2 are in circuit, thus driving the motor at a relatively lowspeed, of about 600 R. P. M., for about one-half minute. Of course thisperiod of one-half minute can be varied, in order to meet any givenconditions.

While the coils2a are in circuit, the solenoid 61 is energized, in orderto operate the magnetically controlled gas supply 30, so as to supplyheat to the apparatus. When the relay armature 64 is operated, it closesthe circuit between the relay points 66, and it `opens the circuitbetween the relay points 64a.

The coil 38 is now cut out of the circuit and the solenoid coil 62 isnow put into the circuit, so that the switch 31 will open, and theswitch 60 will close, so that its arms touch the points 63. This willde-energize the solenoid 61 so that the gas control valve 30 will moveto the closing position. The open position of said gas control valve isshown in Fig. 5.

Current is now supplied to the motor coils 2b, thus driving the motor ata relatively higher speed, as for example about 1200 R. P. M. 'I'hemotor can be driven at this higher speed, while the supply of heat isshut oi, for any desired periodfwhich may be from two minutes to two anda half minutes. In any event the period during which the motor isoperated while the heat supply is shut off is preferably longer than therst period.

After the predetermined period of operation, the time switch 3 moves toopen the circuit completely.

In order to protect the pipes I9 from the dripping of liquid, said pipesare covered by a pan P which becomes heated by the gas burners and thisheat is transmitted upwardly.

The bottom of the compartment 56a, is provided with a drain pipe Wlthrough which the Waste liquid can escape.

The apparatus and method specified herein CII can be utilized for dryingany printing plate, which is subjected to a coating` operation, etc.

The advantage of the double speed whirling is that while the lower speedis being used, the heat sets some of the coating solution on the plate.The subsequent high speed whirls-of the excess of the solution, and thecoating is thor= oughly dried during said high speed operation. Hence amore even coating is secured by the twostage operation, than by whirlingthe plate at a uniform and low speed.

While we have specified the whirling of the plate in the description andclaims, it is to be understood that this is intended to include anysuitable mechanical movement whereby the mois ture is driven off bymechanical force.

We have shown preferred embodiments of our invention, but it is clearthat numerous changes and omissions can be made without departing fromits spirit.

We claim:

1. Apparatus for drying a printing plate, comprising an electric motorhaving a shaft, means for clamping a printing plate to said shaft, saidelectric motor having first driving means and also having second drivingmeans, first switch mechanism for controlling the circuit of the firstdriving means, second switch mechanism for controlling the circuit ofthe second driving means, said switches being normally in the openposition, first electro-magnetic means for moving the first switch tothe circuit closing position, second electro-magnetic means for movingthe second switch to the circuit closing position, the circuit of saidmotor also including a time switch, a time-delay relay having anarmature which closes the circuit of the first electro-magnetic meanswhen in normal position, said armature being moved to a position inwhich it closes the circuit of the second electro-magnetic means after apredetermined interval which is less than the effective interval ofsaidl time switch, said timedelay relay opening the circuit of the firstelectro-magnetic means when it is moved to the last mentioned position,heating means adapted to heat the atmosphere in which the printing plateis located, and electromagnetic means for shutting off the supply ofheat and in circuit with the first driving means.

2. Apparatus for drying a printing plate, comprising an electric motorhaving a shaft, means for clamping a printing plate to said shaft, saidelectric motor having iirst driving means and also having second drivingmeans, first switch mechanism for controlling the circuit of the first idriving means, second switch mechanism for controlling the circuit ofthe second driving means, said switches being normally in the openposition, first electro-magnetic means for moving the rst switch to thecircuit closing position, second electro-magnetic means for moving thesecond switch to thecircuit closing position, the circuit of said motoralso including a time switch, a time-delay relay having an armaturewhich closes the circuit of the first electro-magnetic means when innormal position, said armature being moved to a position in which itcloses the circuit of the 'second electro-magnetic means after apredetermined interval which is less than the effective interval of saidtime switch, said time-*delay relay opening the circuit of the firstelectro-magnetic means when it is moved to the last mentioned position,heating means adapted to heat the atmosphere in which the printing plateis located, and electro-magnetic means for shutting off the supply ofheat and in circuit with the first driving means, the second drivingmeans being adapted to turn the motor at a higher speed than the firstdriving means.

3. In apparatus for drying a printing plate, a vertical shaft and meansfor turning the same, a first shaft extension vertically movablerelative .to said shaft and turnable in unison therewith,

a second shaft extension turnably in unison with the first shaftextension, the second shaft extension being turnable relative to the rstshaft extension around an axis which is inclined to the axis of rotationof said shaft, a third shaft extension anda bearing therefor, the secondshaft extension being reieasably connected to the third shaft extension,said third shaft extension having clamping means for clamping a printingplate thereto, and time-control mechanism for controlling the turning ofsaid vertical shaft in two stages having different speeds.

4. In apparatus for drying a printing plate, a vertical shaft and meansfor turning the same, a first shaft extension vertically movablerelative to said shaft and turnable Vin unison therewith, a second shaftextension turnable in unison with the first shaft extension, the secondshaft extension being turnable relative to the first shaft extensionaround an axis 'which is inclined to the axis of rotation of said shaft,a third shaft extension and a bearing therefor, the second shaftkextension being releasably connected to the third shaft extension, saidthird shaft extension having clamping means for clamping a. printingplate thereto, said bearing having turnable means supporting the same,said turnable means being turnable around an axis which is perpendicularto the central axis of said bearing, and timecontrol mechanism forcontrolling the turning of said vertical shaft in two stages havingdifferent speeds. 1

5. In apparatus for drying a printing plate, a vertical shaft and meansfor turning the same, a first shaft extension vertically movablerelative to said shaft and turnable in unison therewith, a second shaftextension turnable in unison with the first shaft extension, the secondshaft extension being turnable relative to the first shaft extensionaround an axis which is inclined to the axis of rotation of said shaft,a third shaft extension and a bearing therefor, the second shaftextension being releasably connected to the third shaft extension, saidthird shaft extension having clamping means for clamping a printingplate thereto, said bearing having turnable means supporting the same,said turnable means being turnable around an axis which is perpendicularto the central axis of said bearing, and means for holding saidsupporting' means in fixed position, and time-control mechanism forcontrolling the turning of said vertical shaft in two stages havingdifferent speeds.

JOHN PETERS. HAROLD M. CROSBY.

